The embodiments of the present invention relate to an improved connection ring arrangement for an electrical machine, in particular an electric motor.
Electric motors substantially comprise a stator and a rotor. The coils which are required for generating the magnetic fields are arranged in the stator such that the ends of said coils are routed out on an end side of the stator. In order to supply current to the coils of the electric motor, the exposed ends of the coils have to be electrically connected in accordance with the connection scheme (star connection, delta connection).
In existing electric motors, each end of a coil consists of a plurality of wire ends is interconnected. In a first work step, the open ends are connected by crimping, welding or the like. The wire ends, which can comprise an individual wire or ends which are made up of several wires, then have to be electrically connected in accordance with the connection scheme, so that a star connection, delta connection or another suitable circuit connection of the electric motor is achieved.
In existing electric motors, the coil ends are connected by inserting conducting elements which are often referred to as contact ring, connection ring or bus ring. Contact rings of the prior art are produced by complex manufacturing methods. For example, the conductive busbars have to be stamped, rolled or shaped in a similar way. In addition, the insulation resistance between the phases is ensured by complex encapsulation by plastic injection molding in dies. This requires complex and therefore expensive dies for the insulators in the stator for receiving the connection ring.
Existing electric motors, such as Hitachi Metals include connection rings. A plurality of current-carrying rails for the phases U, V, W and, optionally, for a star point with a plurality of plastic spacers, which are encapsulated by injection molding, for fixing and for mutual insulation are known in the prior art.
WO 2012/141135 A1 discloses fixing a plurality of connection rings by means of casting.
DE 10 2008 007 409 A1 describes a connection ring with contact points for receiving wire ends.
JP 2000333400 describes a cast connection ring.
DE 10 2009 020 610 A1 describes a connection spider with three connection rings and a plurality of connection lugs which are arranged on the respective connection rings, wherein the connection lugs of the connection rings are aligned with the connections of the stator, or vice versa. EP 2 110 925 A1 describes a plurality of bus rings which are positioned in relation to one another by means of a plurality of fastening elements.
Objects of the present invention include providing a connection ring arrangement which can be produced in a more efficient manner.
These objects are achieved by a connection ring arrangement having a plurality of conducting rings, wherein each conducting ring is connected to at least one winding of an electric motor. The conducting ring can be a connection ring, a contact ring, a bus ring or the like. The conducting ring can have a circular cross section. The connection ring arrangement further comprises a support element which holds a plurality of conducting rings. The support element has a projection arrangement having two projections which are designed to receive the conducting ring and to extend from said conducting ring. The projection arrangement comprises an open end and a closed end, which closed end receives the conducting ring. The distance between the projections is at least partially smaller than the diameter of the conducting ring and at least one projection is at least partially elastically formed in a direction transverse to the longitudinal direction of the projection. The projections are designed such that the conducting ring is inserted between the projections.
The projections of the projection arrangement can be arranged in the radial direction of the conducting ring. The closed ends of two projection arrangements of a support element can be arranged obliquely in relation to one another. In this embodiment, the conducting ring is held by projections which extend in the radial direction. Since two projection arrangements are arranged obliquely in relation to one another, the conducting ring is held in a stable manner.
The projections of the projection arrangement can be arranged in the axial direction of the conducting ring. The closed ends of two projection arrangements of a support element can be arranged obliquely in relation to one another. In this embodiment, the conducting rings can be arranged in the projections in a particularly simple manner.
A plurality of projection arrangements of the support element can be arranged in the axial direction of the connection ring arrangement, for example when the projections of the projection arrangement extend in the radial direction.
The support element can have a first projection arrangement and a second projection arrangement. The first projection arrangement supports the first conducting ring and is arranged such that the projections are directed in a radially outward direction. The second projection arrangement supports a second conducting ring and is arranged such that the projections are directed in a radially inward direction. As a result, two conducting rings can be arranged substantially one in the other. The two conducting rings can be arranged in a concentric manner.
The support element can have a third projection arrangement and a fourth projection arrangement. The third projection arrangement supports a third conducting ring and the projections of the third projection arrangement are directed in a radially outward direction. The third projection arrangement is arranged in the radial direction in relation to the first projection arrangement. The fourth projection arrangement supports a fourth conducting ring. The projections of the fourth projection arrangement are directed in a radially inward direction. The fourth projection arrangement is arranged in the axial direction in relation to the second projection arrangement. A support element of this kind can receive a particularly large number of conducting rings in a space-saving manner.
The first conducting ring, the second conducting ring, the third conducting ring and the fourth conducting ring can be arranged in a concentric manner.
A plurality of support elements can be arranged on the conducting rings.
The embodiments of the invention also relate to an electrical machine comprising the connection ring arrangement described above.
Other objects, advantages and novel features of the embodiments of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.